How can we count number of contacts associated with accounts?

Hello Saloni,

List<Account> acc=[select Name , (Select LastName from contacts) from Account Limit 10];
for(Account acct:acc){
system.debug('####'+acct.contacts.size());
}

Hi Saloni,

The code for your answer is : -

public class RelatedList
{
public static void ListContact()
{
List accList = [SELECT Name, (SELECT LastName FROM Contacts ) FROM Account];
for(Account acc : accList)
{
System.debug('+++'+ acc.contacts.size());
}
}
}

• This reply was modified 7 years, 4 months ago by  shariq.

Hi,

simple query :-
SELECT count(Id) FROM Contact Where AccountID='00141000015cS58'
---Soql query to count total contact related to an account -----

List<AggregateResult> results=[SELECT count(Id) FROM Contact Where AccountID='00141000015cS58']; //count() return AggregateResult type value
integer total_contact = Integer.valueOf(results[0].get('expr0') + '');
//integer total_contact=(Integer) results[0].get('expr0');
system.debug('total contact of Internal Queries : '+total_contact);

And trigger  to show count on a custom field:

trigger FindContactsCount on Contact (after insert, after update, after delete) {

List<Contact> modContacts = Trigger.isDelete ? Trigger.old:Trigger.new;
Set<Id> accIds = new Set<Id>();
for (Contact c: modContacts) {
accIds.add(c.AccountId);
}
List<Account> modAccounts = [Select Name, (Select Id from Contacts) from Account WHERE Id in: accIds ];

for (Account a: modAccounts) {
List<Contact> s = a.Contacts;
System.debug('Account:' + a.Name + ' No. of Contacts: '+ s.size());
a.No_of_Contacts__c = s.size();
}
}

Hope this code will help you and others 🙂